Cardiac features such as septal defects and atrial appendages often contribute to cardiac blood flow disturbance, which is associated with a number of cardiac-related pathologies. For example, complications caused by blood flow disturbance within the left atrial appendage (LAA) and associated with atrial fibrillation can be a contributor to embolic stroke. The LAA is a muscular pouch extending from the anterolateral wall of the left atrium of the heart and serves as a reservoir for the left atrium. During a normal cardiac cycle, the LAA contracts with the left atrium to pump blood from the LAA, and generally prevents blood from stagnating within the LAA. However, during cardiac cycles characterized by arrhythmias (e.g., atrial fibrillation), the LAA often fails to sufficiently contract, which can allow blood to stagnate within the LAA. Stagnant blood within the LAA is susceptible to coagulating and forming a thrombus, which can dislodge from the LAA and ultimately result in an embolic stroke or other thromboembolic complication.
In some instances, thrombus formation in the LAA of arrhythmic patients can be minimized by occluding the LAA. Some LAA occlusion devices that are placed within the LAA or across the ostium of the LAA (the opening between the left atrium and the LAA) terminate at an elongate eyelet at each end of the device. The elongate eyelet of the device that faces the left atrium after implantation can often protrude from the device into the left atrial chamber, which can disturb blood flow within the left atrial chamber and can lead to thrombus formation and accumulation near the eyelet. Furthermore, a protruding eyelet may present a blood-material interface that is different than that which exists along other atrial-facing regions of the occluder device. Thrombus formation may increase the risk of stroke, and serious injury or death can result if the thrombus becomes dislodged and enters the circulatory system.